The one thing that is making the implementation of BIM (Building Information Modelling) on Projects very difficult and frustrating is what I call “pseudo BIM”, killing any initial enthusiasm to use BIM, and leading to generalisation statements in industry like “BIM costs more” or “BIM is expensive” and “BIM is too difficult”.
More people practice “pseudo BIM” than you would imagine, and unsuspecting clients, who can’t spot the difference, are being “sold a pup”.
So what is “Pseudo BIM”?
To answer this, I need to explain the difference between the traditional process of creating, managing and exchanging design and construction information, with a true BIM process.
The Traditional Approach.
The traditional process of communicating design and construction information involves the production of “documents”, separately produced 2-dimensional drawings, schedules, and specifications. In this process, the information about the building and components can be produce a number of times, in plan, elevation, section, detail view, listed in a schedule, and described in a specification. Coordinating all these “documents” to make sure they describe the same thing, requires manually checking. If a change is required, this change has to be made and coordinated across all these separate documents. This is prone to human error, and conflicts in the documents result in misunderstanding, delays, variations, cost overruns and disputes. The exchange of information between stages is usually paper, or static digital copies of the “documents” (e.g. PDF). This isn’t digital data that can be extracted, queried or edited, so it usually involves the next party having to absorb the cost and time to re-create the information in their systems in order to do their work. It is all these issues which BIM aims to address.
The BIM Approach.
BIM is about constructing a digital virtual 3-dimensional building, from objects (components) that represent their real-life counterparts. In comparison to the traditional approach above, in BIM you only describe the building components once, in the 3D model, and each object, is a digital container, or placeholder of all the relevant information about that component. In the virtual 3D environment, people can look around and immediately appreciate and understand what the building is, and how everything works together. The software can even automatically find clashes between objects. They can click on objects, and see all the relevant information. They can query or extract this information to use in other processes, like project planning or sequencing (4D BIM) quantity take-off and cost checking (5D BIM), detailed analysis for structural performance, energy performance etc. (6D BIM), or operations and maintenance information (7D BIM). In other words, the effort of describing the objects once, can be leverage multiple times by multiple people for multiple purposes. And of course, let’s not forget about “the documents” we have to produce – drawings and schedules are “views” generated from the model, for output for record purposes (the real value is in the model, not the documents). These only have to be set-up, they are not manually produced, and since they are all being derived from the same digital database, they are all automatically coordinated. If a change is required, you make that change once in the 3D model, and all of the “views” are automatically updated.
So you can see, when comparing the traditional approach, with a true BIM approach, that the latter is a far more efficient, and therefore less time-consuming, and therefore less costly way of working. The 3D models are easier for everyone to understand, and also result in better design coordination, and therefore fewer potential errors for misunderstanding, delays, variations, cost overruns and disputes.
So what is “Pseudo BIM”?
Now that you understand the difference, let me explain “Pseudo BIM”. For a variety of reasons (lack of skills, lack of resources, wanting to re-use legacy information etc), some companies are continuing to produce information in the traditional approach, but are adding BIM on top of that, if it is a client requirement. In other words, they are producing the 3D model afterwards, or in tandem with traditional drawings, schedules, specifications etc. When you approach BIM this way, then of course it is going to add expense, time, frustration and difficulty. It is unlikely that all the information will find its way back into the model. It also means there will be potential conflicts between the drawings, schedules and the model, as they are all produced separately. And these conflicts continue to result in misunderstanding, delays, variations, cost overruns and disputes. So a “pseudo BIM” approach, doesn’t really resolve any of the issues associated with the traditional approach.
It is important to understand, that a true BIM approach is not something you can add on top of a traditional approach – it is a completely different way of working – an alternative approach that has many potential benefits, for everyone, but only if everyone on the project works in this way. Unfortunately, the benefits are being eradicated by some companies’ insistence on using “pseudo BIM”, and not delivering what clients are asking for, which is a true BIM process.
No More “Pseudo BIM” Please